Picked up a couple of CO2 tanks at an auction recently, and was hoping someone else on here has a similar set up for inboard air. I'm sure I'll have to get the tanks recertified, but what type of regulator do I need to make this all happen? Anyone have these on their rigs? They're great for running air tools for repairs and airing up tires after a day of wheeling.. what kind of volume can be expected from a 2' tall x about 10" diameter tanks?

If they are out of cert, sometimes it's cheaper to swap for tanks at your local suppler than to get them certified.
I had some tanks I was having refilled, drop them off, wait, pick them up, you know the drill,
The guy told me he would swap me their tanks for like $20 a year extra since I had my own,
NO MORE WAITING, just drop and pick up another tank, Worth the $20...
RENTING their tanks was another story, fairy expensive, but since you have your own, you might look into a trade.

If the guy hadn't tipped me off, I would have never known...
It's actually how they poach customers from other sources, a cheap foot in the door.

They did the same thing with the little 'China' tank that came with a welder,
I went to have it filled, they said it couldn't be filled (no DOT cert), and swapped me a certified standard size tank for it for $25...

Torque comes from the volume the regulator can pass, and most regulators don't pass a lot of volume.
They will inflate a tire, but you can't get enough volume to bead a tire with one (or normal air tanks most times).
That's why they make those 'Cheetah' tanks that dump everything all at once, HUGE volume...

If you are aiming for just filling up tires and such, then consider a smaller volume regulator, like they use on soda machines,
They are everywhere, cheap, but don't pass the volume you would need for air tools...
I had the same problem, not enough volume through the regulator for tools to do much work.
Wouldn't even keep up with an air drill...

My CO2 rig would inflate my 37" tires 3, some times 4 times, but the size of the tire has a lot to do with things and how far you air down.

I gave up when we wheeled a lot and went with an electric compressor.
Still use it instead of a little "Rescue" air tank for the tow vehicle and around the farm, works pretty good for that stuff.

What I never got used to was making sure the tank was full BEFORE we left out!
Always half way through SOMETHING when the CO2 ran out!
I should have got a second tank and rotated them so one was always full.
You won't have that problem, you have a second tank.

Thanks again JH, so let's talk nitrogen instead of CO2, someone mentioned to me a while back, that you can get about 2500 psi of nitrogen in one of these tanks.. how does this compare to a CO2 charge, for longevity, or available volume?

I have a 10# CO2 tank and it takes a little over a pound to air up 4 33" tires from 12# to 28#. I now have 35" tires but I have not used the CO2 on the 35s yet. One characteristic of CO2 is that it turns to liquid at 600psi at normal temps. I don't want to ride around with a 2500psi pressurized vessel in my Jeep. I can live with 600psi tied down in a fire extinguisher bracket.

I suppose you could get a regulator at a welding shop that has guages but the one I bought is fixed 150psi and was about $50. I had to order it online some years ago. I got it custom made at a company which specializes in helium balloon equipment.

I don't know the size or pressure your tanks will hold, so I have no idea, and I've not messed with nitrogen at all except in the race cars, and we use a vendor for that.

Most of the aluminum tanks are rated for 2,200 PSI that I've seen,
Steel is a little more, but I didn't run steel tanks, so I can't tell you exactly how much more, I *Think* it's 2,500 PSI.

Aluminum scuba tanks are rated for 3,000 and 3,300, but they are MUCH heavier than the CO2 tanks I used and a little larger also.

Fighter 'Air Pack' tanks used to be rated for 1,800 and 2,200, but I don't know what they are these days...

Some tanks can't be re-purposed, And I don't know which ones can and can't, those would be questions for the local 'Air-Gas' distributor that deals with tanks.
There are a BIG BALL of federal and state rules that I don't keep up with, and they will be the guys current in all that stuff...

In the end, they usually offer you one of THERE tanks for cheap just to stay complaint...

...I suppose you could get a regulator at a welding shop that has guages but the one I bought is fixed 150psi and was about $50. I had to order it online some years ago. I got it custom made at a company which specializes in helium balloon equipment.

I wish I'd found a $50 regulator!
I paid almost $150 for mine, has both gauges, which keep getting broken off so there goes another $30 every time they do,
And you can't keep the little monkey fingers off an adjustable regulator!

Everyone that sees it has to play with the regulator adjustment, so a fixed regulator would be a GOOD DEAL!

This may be old data. I don't know if these guys are in business anymore but at one time you could call them and get a fixed regulator built to any psi you wanted.
The way I tell how much CO2 I have is that my 10# tank weighs 14# empty and 24# full. So I just weigh the tank.

The best part about the 150 psi regulator was that I could fill a 33" tire from 12# to 28# in about 55 seconds while it takes minutes for the guys who have the smittybilt electric air compressors. The main advantage of the CO2 system is speed.

This is kinda hyjacking the thread, but there is a trend in the discussion that warrant some cautions.

The problem with using scuba and scba tanks (scba,what fireman use) is that they are both used for breathing so all regulators that fit will only give low volume. as noted by Foggybottombob, fill rates are much faster with a higher pressure regulator but those are not available for air (atmospheric air) tanks, ie they will not screw into the air tank. At the pressures in the air tanks, fittings should NEVER be adapted, it is VERY DANGEROUS. And fill stations, 99.9% of the time, will refuse to fill an "adapted" tank.

Noted by JH, air tanks PSI usually starts at 2200 and now some scba tanks are filled to 4400psi. Oddly the scba tanks are now thin aluminum and fiber glass wrapped (FGW), making them very light for the fireman (scuba tanks have to stay heavy so they will sink). But there is the same problem with fitting them to high volume regulators. Too bad because the light weight would be great for jeep applications. And they can still be used, but as FoggyBB noted, it takes longer. I tried using compressed air tanks (scuba tanks) for a while, its just slow, so I went to oba. If anyone wants to try it, I have about 70 scuba tanks for sale and can coach you how to set up a regulator.

There is often confusion between air and oxygen tanks. They are not the same. Oxygen tanks can be fitted with higher volume regulators but at high pressure, oxygen the gas, is very Volatile and what ever contains it (tank, lines, regulators, etc.) must be very clean, what is know as O2 clean. Tires are not O2 clean and oxygen should NEVER be used to fill tires. There are many incidents of welders stuck in the field with a flat tire "airing up" the tire with oxygen from their tank only to be killed by the explosion from the tire, or it exploded later when the person using the tire machine is killed or injured. O2 explosions are very very powerful. This is important, never ever fill tires with oxygen.

I know that CO2 is used a lot in jeep applications (and paint ball guns too). It is great because it is a liquid (technically a solution) until it is released where it turns to gas so for inflating things, it goes a long way.

In the petroleum industry where I live, CO2 is used to inject into oil formations to increase oil production. It is big business in the oil industry.

However
CO2 is a corrosive gas. Because it is a big business here, there is lots of products made to counter the corrosion, stainless still and specialized fittings etc.

When I first heard of using CO2 to fill tires, knowing that it was corrosive, but still widely accepted with jeep folk, I ask some engineers who work with it every day. They confirm, CO2 will eventually corrode your steel and aluminum wheels. I decided not to use it. I know it is accepted a lot, I would like to see the long range effect on wheels using CO2.

Final note, I "threw" a lot of "authority" in the discussion above. Not trying to "toot my horn". I hve good knowledge about the subject. I am a certified tech for most every scuba regulator made including those used for NITROX (an oxygen enriched air for scuba). And I am also a CGA certified hydrostatic tester. CGA (Compressed Gas Association) guidelines are adopted by USDOT as if their own.

This is kinda hyjacking the thread, but there is a trend in the discussion that warrant some cautions.

The problem with using scuba and scba tanks (scba,what fireman use) is that they are both used for breathing so all regulators that fit will only give low volume. as noted by Foggybottombob, fill rates are much faster with a higher pressure regulator but those are not available for air (atmospheric air) tanks, ie they will not screw into the air tank. At the pressures in the air tanks, fittings should NEVER be adapted, it is VERY DANGEROUS. And fill stations, 99.9% of the time, will refuse to fill an "adapted" tank.

Noted by JH, air tanks PSI usually starts at 2200 and now some scba tanks are filled to 4400psi. Oddly the scba tanks are now thin aluminum and fiber glass wrapped (FGW), making them very light for the fireman (scuba tanks have to stay heavy so they will sink). But there is the same problem with fitting them to high volume regulators. Too bad because the light weight would be great for jeep applications. And they can still be used, but as FoggyBB noted, it takes longer. I tried using compressed air tanks (scuba tanks) for a while, its just slow, so I went to oba. If anyone wants to try it, I have about 70 scuba tanks for sale and can coach you how to set up a regulator.

There is often confusion between air and oxygen tanks. They are not the same. Oxygen tanks can be fitted with higher volume regulators but at high pressure, oxygen the gas, is very Volatile and what ever contains it (tank, lines, regulators, etc.) must be very clean, what is know as O2 clean. Tires are not O2 clean and oxygen should NEVER be used to fill tires. There are many incidents of welders stuck in the field with a flat tire "airing up" the tire with oxygen from there tank only to be killed by the explosion from the tire, or it exploded later when the person using the tire machine is killed or injured. O2 explosions are very very powerful. This is important, never ever fill tires with oxygen.

I know that CO2 is used a lot in jeep applications (and paint ball guns too). It is great because it is a liquid (technically a solution) until it is released where it turns to gas so for inflating things, it goes a long way.

In the petroleum industry where I live, CO2 is used to inject into oil formations to increase oil production. It is big business in the oil industry.

However
CO2 is a corrosive gas. Because it is a big business here, there is lots of products made to counter the corrosion, stainless still and specialized fittings etc.

When I first heard of using CO2 to fill tires, knowing that it was corrosive, but still widely accepted with jeep folk, I ask some engineers who work with it every day. They confirm, CO2 will eventually corrode your steel and aluminum wheels. I decided not to use it. I know it is accepted a lot, I would like to see the long range effect on wheels using CO2.

Final note, I "threw" a lot of "authority" in the discussion above. Not trying to "toot my horn". I hve good knowledge about the subject. I am a certified tech for most every scuba regulator made including those used for NITROX (an oxygen enriched air for scuba). And I am also a CGA certified hydrostatic tester. CGA (Compressed Gas Association) guidelines are adopted by USDOT as if their own.

I wonder if I should do a more complete write up on the subject??

As to the SCBA tanks, this is what I use in one of my trail Jeeps.
It is a 80 cubic foot bottle.
Fire departments use these bottles and regulators for a number of air tools, air chisels being the main tool. The CFM/PSI depends on the regulator.
I fill 4, 36/13.50/15 IROC's from 4 to 20PSI. 4 times, with 800 PSI left in the tank. Just as fast as the guys with York OBA and a 6 gallon tank.
After every use the regulator is removed and the tank shut off.

Here's a picture of the regulators we/I use. Granted it was expensive.
On edit, all of the new SCBA bottles we buy are Kevlar wrapped to my knoweledge.
Bill

__________________
1957 WILLYS pickup, needs work.
1973 J 4000,
1978 CJ7 DD.
1979 CJ7 360, TH400/Quadratrac trail Jeep.
1979 J20
1980 CJ5 trail Jeep.
1983 CJ7 pretty weekend and sometimes to work Driver in the summer, My first rebuild, if the Q-trac and 5 are broke, this one is the one to take. its just as capable as the other 2, except nice paint.
1984 Grand Wagoneer, 1 ton axles, great 360/727, and a big a$& tree fell on it .
1989 YJ the CJ to YJ conversion.
2005 TJ Rubicon.
2011 Grand Cherokee Laredo 4x4, Mrs. LUCDOG's DD.
Lots of parts not for sale, i'm a hoarder.